Combined rubber dam and tooth-backing punch.



No. 888,297. PATENTBD MAY 19, 1908.

H. M. BELL. I COMBINED RUBBER DAM AND TOOTH BACKING PUNCH.

AiPLICATION IIIIED JAN. 21, 1907.

Svwenfoz Witnesses 1 sprin UNITED STATES PATENT OFFICE. I

HARRY 1N1. BELL, OF HOUSTON, TEXAS.

COMBINED RUBBER DAM AND TOOTH-BACKING PUNCH.

Application filed January 21, 1907.

T 0 allwhom it may concern:

Be it known that I, HARRY M. BELL, a citi- Zen of the United States, residing at Houston, in the county of Harris, State of Texas, have invented certain new and useful improve ments in Combined Rubber Dams and Tooth- Backing Punches; and 1 do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to new and useful improvement in dental instruments and more particularly it has references to a punch for forming holes accurately in the backing which is used on teeth in the construction of bridges, plates, and cognate work, and which, when not in use as a backing punch, may, by slight chan es in the arrangement of certain parts be uti ized as a dam punch.

In connection with a device of the above type the invention aims as a primary object to provide a novel construction, combination and arrangement of parts, the details of which will appear in the course of the following description, in which reference is had to the accompanying drawings, like characters of reference desi nating similar parts throughout the severa views, wherein:

Figure 1 is a plan view of the upper member embodied in the punch constructed in accordance with the present invention, the or being shown in dotted lines. Fig. 2 is a plan view looking at the inner face of the lower member of such punch. Fig. 3 is a side elevation with the parts assembled for use. Fig. 4 is a front end elevation of the punch.

The invention constructed in the, embodiment shown comprises upper and lower members 1 and 2, having crossed handles 3 and 4, which are pivotally connected at their intersection as at 5. A leaf spring 6 is fixed at 7 arbitrarily to the handlegl and at its free end is formed with an enlarged knob or bead 8 which bears against the handle 3, the pressure of the s ring 6 tending to hold the members normally apart so that in use they are moved together against the influence of such s ring. The member 1 is formed with a lon gitudinal recess 9 of hour glass shape which extends to the front edge thereof and in which are received conformably shaped blocks 10, the latter being formed with punches 11, pointing towards the member 2, and in their upper surfaeeswith recesses 11 Specification of Letters Patent.

Patented May 19, 1908.

Serial No. 353,404.

to receive the pins of the teeth. The said member 2 is formed along its inner face with a dove-tail recess 12, extending to the front edge thereof, andin which is disposed at bed of hard cork or similar material 13.

The member 1 has its upper face formed at one side of the recess 9 with a scale 9 having its calibrations extending transversely of said member and at the other side of the recess 9 with a scale 9" having its calibrations extending lingitudinally of said member.

The lower member 2 has its upper or innerface formed with a scale 14 similar to the scale 9 and on the same relative side of the member 2 and with a scale 14 similar to the scale 9 and on the same relative side of the member 2. The scales 9 and 9" and 14 and 14 are employed for the purposes of insurmg accuracy in use.

A leaf spring 15 is secured to the member 1, and overlies the outer face thereof. This spring is provided merely for the purpose of convenience in holding one or more teeth during the use of the instrument. The member 2 is constructed with depending angular brackets 16 in which is slidably mounted a tray 17, the latter being employed to hold the dam punches.

The blocks 10 are constructed with threaded bores and the punches 11 have theirv the blocks 10 are adjustably movable to permit of such engagement in accordance with the distance between the pins, which of course will depend on the width of the teeth. The teeth are held from disengagement by the spring 15. The operator then measures the distance between the pins on the scale 9 and places the metallic sheet of backing upon the bed 13 using the scale 14 as a guide for positioning said backing so that when the punch is mani ulated, the holes made by the punches 11 wi 1 be the same distance apart as the pins on the teeth in their disposition in the recesses 11. The scales 9 and 14" afford a means for insuring of the accurate positioning of the angular sides of the backing sheet to correspond to the proportion and position of the base of the tooth. When it is desired to punch rubber dams, dam punches of suitable forms are substituted for the punches 11 and the device is used in similar manner.

A punch constructed in accordance with the present invention is sim le, inexpensive to manufacture and practicaFand efficient in use.

From the foregoing description it will be seen that simple and eflicient means are provided for accomplishing the objects of the invention, but while the elements herein shown and described are well adapted to serve the functions set forth it is obvious that various minor changes may be made in the proportions, shape and arrangement of the several parts, without departing from the spirit and scope of the invention as defined in the ap pended claims.

What is claimed is:

A device of the type set forth comprising H front edge thereof, conformably shaped blocks detachably engaged in said recess, pins carried by said blocks and pointing towards the lower member, the lower member being formed with a dove-tail recess extending longitudinally from the front edge there of and a bed of hard cork disposed in said recess.

In testimony whereof, I affix my signature, in presence of two witnesses.

HARRY M. BELL.

Witnesses:

J. MooDY DAWSON, W. U. MARTIN. 

